# -*- codeing =utf-8 -*-
# @Time : 2022/9/12 下午2:54
# @Author :WXJ
# @File : 2.2.py
# @Software: PyCharm

'''
n =100
sum=0
counter =1
while counter<=100:
    sum=sum+counter
    counter+=1
print("1到100的和%d"%sum)
'''



result=0
for i in range(101):
    result+=i
print(result)